8-Oxo Guanosine nucleotides are used for random mutagenesis of DNA. 8-Oxo-dGTP can be incorporated by PCR but hybridizes with Adenosine instead of Cytidine, whereas the Cytidine analog dPTP hybridizes with Thymidine instead of Guanosine.
Check out the DNA Mutagenesis section → Molecular Biology for Mutagenesis Kits and more detailed information.